JP2590921B2 - One-component development method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a one-component developing method for performing development using a layer regulating member.

(Prior Art) Conventional one-component developing methods are broadly classified into a contact type in which a developer layer regulating member is brought into contact with a developer carrier and a non-contact type.

As the contact-type layer regulating member used in the one-component developing device, a metal material exhibiting spring elasticity, such as phosphor bronze, silicon steel, stainless steel, or the like, or a plate spring material made of a resin film or the like, A material in which a soft elastic body is adhered to a leaf spring material for the purpose of effectively imparting an electric charge to the agent and for reducing the stress applied to the developer,
An example is a rectangular flat plate having rubber elasticity.
Conventionally, the developer layer is regulated by using the flat surface of the layer regulating member as shown in FIG. That is, the layer regulation of the developer 1 in the hopper 2 is performed such that the plane of the layer regulation member 5 abuts on the developer carrying roll 4.

(Problems to be Solved by the Invention) However, when one-component development is performed using a conventional contact-type layer regulating member, there are the following disadvantages.

(1) When the developer layer is controlled by directly pressing against the developer using the leaf spring material, the developer is crushed during development or adheres to the layer regulating member such as the leaf spring material with time. For this reason, a developer layer which is stable over time cannot be obtained.

(2) When a soft elastic member is used to prevent the developer from being crushed or adhered to the layer regulating member, a contact portion of the member with the developer carrier is worn, and the member and the carrier are worn. Since the contact pressure gradually decreases, a phenomenon occurs in which the thickness of the developer layer increases or spills over time, resulting in a lack of long-term reliability.

In order to solve the problem (1), the problem (2) occurs, and to solve the problem (2), the problem (1) occurs. The life of the member has been shortened, and it has been necessary to replace it in a short period of time.

The present invention has been made to solve the above-mentioned drawbacks in the prior art.

Accordingly, an object of the present invention is to provide a one-component developing method capable of forming a high-quality copy image while maintaining the reliability of development for a long time.

(Means for Solving the Problems) The present inventors have found that the above-mentioned problems in the prior art are as follows. When performing a phenomenon using a one-component developing device, the contact state of the layer regulating member is set to a specific state. It has been found that the above-mentioned problems can be solved by controlling the above-mentioned conditions, and the present invention has been completed.

According to the present invention, a layer forming member is brought into contact with a developer carrier to form a uniform layer of developer on the developer carrier, and the developer carrier is formed on the photoconductor by facing the photoconductor. In the non-magnetic one-component developing method for developing the formed electrostatic latent image, a flat elastic body obtained by bonding a flat soft elastic body to a flat spring member is used as the layer regulating member. Alternatively, a region including one edge of the rear end portion is pressed against the developer carrying member to regulate the layer.

 The present invention will be described with reference to FIG. 2 corresponding to the embodiment.

FIG. 2A is a perspective view of a layer regulating member used in the present invention,
(B) is an explanatory view for explaining a state in which it is used.

The layer regulating member 5 used in the non-magnetic one-component developing method of the present invention has a structure in which a flat soft elastic body 8 having a predetermined thickness is adhered to a leaf spring member 7. As the leaf spring material, a metal material exhibiting spring elasticity, for example, phosphor bronze, silicon steel, stainless steel, or a resin film is used. Further, as the soft elastic body, silicone rubber, natural rubber, SBR, acrylic rubber, fluorine rubber, polychloroprene, polyisoprene, or the like is used. In addition, a mixture of a soft elastic body and a charge control agent can be used in order to enhance the function of imparting charge to the developer. As the charge control agent, a compound used as a charge control agent for a toner can be used as it is.

In the present invention, the above-mentioned layer regulating member is brought into contact with the developer carrying member, and the contact is made by A, A at the tip of the soft elastic body 8 of the layer regulating member 5 as shown in FIG.
What is necessary is just to make the area | region including the edge CD of the surface formed of B, C, and D contact the developer carrying roll 4 so that it may press-contact.

In addition, the leaf spring material of the layer regulating member may have a shape in which an edge is bent for the purpose of preventing bending.

(Operation) According to the conventional method, the developer layer is regulated using the lower surface of the layer regulating member. Therefore, the nip area is widened due to the wear of the layer regulating member, the pressure acting on the layer regulation is reduced, and the effect is reduced. Layer control is not possible, and the developer spills out of the developing machine in a short time. In the present invention, the layer regulating member is worn over time, but the spread of the contact area between the developer carrier and the layer regulating member can be minimized as compared with the conventional method. It is presumed that the developer layer can be maintained in a range that does not substantially affect the developer layer, despite the fact that it has decreased. Therefore, according to the present invention, the amount of wear of the layer regulating member is reduced as compared with the conventional method, so that a long-term stable contact pressure can be obtained and the contact area can be prevented from expanding.

EXAMPLES Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited thereto.

FIG. 1 is a schematic view of a developing device for explaining the present invention, in which a developer carrying roll 4 is disposed on a hopper 2 containing a developer 1, and a layer regulation is provided on the surface of the developer carrying roll. The member 5 is in contact. As a developer carrying roll, a roll having a stainless steel cylindrical sleeve having a diameter of 3 cm and a length of 40 cm was used. The layer regulating member 5 is made of SUS304.
And a soft elastic body 7 made of silicone rubber having a charge-imparting function.

The developer composition used in this experiment is as follows.

Styrene / n-butyl methacrylate (70/30) copolymer (Mu: about 15,000, Mw: about 40,000) 90 parts Carbon black 9 parts Metal-containing dye 1 part The above components are melt-kneaded by a roll mill and ground by a hammer mill. Thereafter, the resultant was finely pulverized by an air jet method and further classified to obtain a toner having an average particle diameter of 12 μm.

The following fine powder was added to the above toner, and stirred with a high-speed mixer to prepare a developer.

Hydrophobic silica (average particle size: 0.016 μm, manufactured by Nippon Aerosil Co., Ltd.) 1.0% by weight The layer regulating member 5 was pressed in such a manner that only one end of the soft elastic body at the tip end thereof was in line contact with the developer carrying roll. . This developing device is arranged with a gap of 300 μm from the photoreceptor, a developing bias is applied, and A4
A copy test was performed at the speed of 50 sheets of size paper. 100,
000 copies were made, and a good image was obtained which was not different from the initial one.

Further, in this case, the changes in the developer amount and the charge amount per unit area on the pre-development support were measured. The changes in the amount of developer and the amount of charge per unit area were extremely stable as indicated by the black dots in FIGS. 5 and 6.

For comparison, a copy test was performed in the same manner with the layer regulating member in contact with the state shown in FIG.
When 0 copies were made, fogging occurred on the copy, and on the 10,000th copy, toner drips from the developing device were observed on the copy paper.

Similarly, changes in the developer amount and the charge amount per unit area on the developer carrying roll were measured. The results are shown in FIGS. 5 and 6. FIGS. 5 and 6 show changes in the amount of developer and the amount of charge per unit area as white points, but were unstable over time.

In the above embodiment, as shown in FIG. 3 (a), only one end edge of the front end portion of the soft elastic body 8 of the layer regulating member 5 is pressed so as to be in line contact with the developer carrying roll 4. As shown in FIG. 3 (b), the surface including one end edge of the leading end may be changed so as to be in pressure contact with the developer carrier 4, and as shown in FIG. The elastic body 8 may be changed so that only one end edge of the rear end portion or a surface including the one end portion comes into pressure contact with the developer carrying roll 4.

FIG. 7 is a schematic cross-sectional view of another example of the one-component developing apparatus used for performing the non-magnetic one-component developing method of the present invention. As shown in FIG. 7, the developer carrying roll 4, the layer regulating member 5, and the developer supplying member 3 are housed in a hopper. A layer regulating member 5 in which a leaf spring member 7 provided with a soft elastic body 8 at its tip is supported on a support 9 is in contact with the surface of the developer carrying roll. More bias voltage is applied.

In this apparatus, a developer 1 in a hopper 2 is supplied onto a developer supply member 3 by gravity, and a developer carrying roll 4 is rubbed against the developer supply member 3. Is frictionally charged and adheres to the surface of the developer carrying roll 4. Thereafter, the layer regulating member 5 is brought into contact with the developer 1 attached to the surface of the developer carrying roll 4,
The rubbing imparts more sufficient charge to the developer and forms a uniform thin developer layer on the surface of the developer carrying roll 4. Further, a developer seal member 12 is provided between the lower portion of the hopper 2 and the developer carrying roll 4, thereby performing sealing.

When the developer in the form of a thin layer formed on the surface of the developer carrying roll 4 reaches the developing area facing the photoreceptor 10, the developer flies due to the charge of the electrostatic latent image formed on the surface of the photoreceptor 10. And visualizes the electrostatic latent image. The developer carrying roll 4 that has passed through the developing area passes through a developer sealing member 12 provided at a lower portion of the developing device, and is returned into the hopper 2 with the remaining developer adhered to the surface thereof.

In the one-component developing device configured as described above, the developer 1 in the hopper 2 is frictionally charged by the friction between the developer supply member 3 and the developer carrying roll 4 to be given an electric charge, and While being attached to the surface of the roll 4 and being made into a thin layer of a predetermined thickness by the layer regulating member 5, a sufficient charge having a predetermined polarity is applied by the action of sliding. The developer thin layer 6 is moved to a development area facing the photoconductor 10 by rotating the developer support roll 4 while applying a DC superimposed AC bias voltage to the developer support roll 4, and It flies toward the electrostatic latent image due to the electric field between the electrostatic latent image on the surface and the developer carrying roll 4, and adheres on the electrostatic latent image to visualize the electrostatic latent image.

(Effect of the Invention) In the non-magnetic one-component developing method of the present invention, as described above, the layer regulating member is formed by bonding a plate-shaped soft elastic body having a predetermined thickness to a leaf spring member. Since the region including the one end edge of the front end portion or the rear end portion of the elastic body is pressed against the developer carrying member to control the layer thickness of the developer layer, as is clear from the comparison in the above embodiment, The developer is not crushed with the lapse of time, the developer does not adhere to the layer regulating member, and the layer thickness of the developer layer increases or the developer spills. Nothing. Therefore, a copy with good image quality can be obtained even for a large number of copy operations.

[Brief description of the drawings]

FIG. 1 is an explanatory view illustrating a schematic configuration of a developing device for carrying out the present invention, FIG. 2 (a) is a perspective view of a layer restricting member used in the present invention, and FIG. Explanatory drawing explaining the contact state, FIGS. 3 (a), (b) and (c)
Is an explanatory diagram illustrating the contact state of the layer regulating member used in the present invention, FIG. 4 is an explanatory diagram illustrating the contact state of the layer regulating member in the conventional method, FIG.
FIG. 6 is a graph showing the change over time of the developer weight in the embodiment of the present invention, FIG. 6 is a graph showing the change over time of the charge amount in the embodiment of the present invention, and FIG. FIG. 2 is a schematic sectional view of an example of a component developing device. DESCRIPTION OF SYMBOLS 1 ... Developer, 2 ... Hopper, 3 ... Developer supply member, 4 ... Developer carrying roll, 5 ... Layer regulating member, 6 ...
... developer layer, 7 ... leaf spring material, 8 ... soft elastic body, 9 ...
... Support, 10 ... Photoconductor, 11 ... Bias power supply, 12 ...
Seal member.

Claims (1)

(57) [Claims] An image forming apparatus according to claim 1, wherein a layer forming member is brought into contact with the developer carrying member to form a uniform layer of the developer on the developer carrying member. In the non-magnetic one-component developing method for developing the formed electrostatic latent image, a flat elastic body obtained by bonding a flat soft elastic body to a flat spring member is used as the layer regulating member, and a tip of the flat elastic body is used. A non-magnetic one-component developing method, wherein a layer including one end of a portion or a rear end portion is pressed against a developer carrying member to regulate a layer.